The aggressive therapy used to eradicate cancer cells and prevent rejection of the transplant can lead to long-term medical complications for a decade or so.

Wing Leung, MD, PhD, director of Bone Marrow Transplantation and Cellular Therapy, St. Jude Children’s Research Hospital, was co-leader of a recent study of the long-term effects of hematopoietic stem cell transplants (HSCT) on children. While HSCT can save children, the aggressive therapy used to eradicate cancer cells and prevent rejection of the transplant can lead to long-term medical complications for a decade or so; and this problem is growing, since more and more children are surviving allogeneic HSCTs. Allogeneic transplants are those obtained from a genetically similar but not identical donor.

Leung and former St. Jude researcher Hyunah Ahn led a team of investigators in a comprehensive series of annual tests on 155 patients who survived HSCT in order to identify the “late events” (medical problems linked to therapy that occur years after discharge from the hospital) they experienced.

The researchers found that only 20 (13 percent) of the 155 patients had no medical problems related to HSCT, while 18 (12 percent) had one long-term health problem, 71 (46 percent) had two to four conditions and 46 (30 percent) had five to nine conditions.

In addition, the investigators identified five risk factors that made children vulnerable to late complications. Three of these factors were related to treatment: total body irradiation, higher radiation dose and graft-versus-host reaction. The other two were patient related—specifically, being female and being younger in age at the time of HSCT.

“One key finding was that many people had more than one endocrine problem,” Leung said. “This suggests that patients should undergo comprehensive tests for various endocrine problems rather than just for certain hormone deficiencies, since hormone therapy could improve the lives of these young survivors.”

“The practical use of our findings is that such information would help the patient’s hometown physician anticipate potential late term events following HSCT,” said Ching-Hon Pui, MD, St. Jude’s Oncology chair. “Primary health care providers who know the clinical history and risk factors of patients who have had HSCT can improve the quality of life for such patients by identifying and treating these complications early.”